Loss of keyboard echo

["Mark Verschell" <verschell@xxxxxxxxxxxxxxxxxxxxx>]

There is a problem that has occasionally popped up on the list serve that has
never been answered to the best of my knowledge. It seems that a certain order
or number of commands to ferret will cause the keyboard echo to turn off, which
leaves you with:

yes? yes? yes? yes?

If you try to continue with the ferret session - the program still runs, but
command echo disappears; in addition the output of commands like list or stat
are displayed without <CR><LF>'s. When this happens is very machine and display
dependent. I have come up with the shortest repeatable example that I know of
that leads to this problem. This is ferret v4.91 running under Irix 6.5.1,
displaying on a PowerMac running MacX (an X-windows emulator). Here is the .JNL
file:

yes? use uv.230-2325.noip.cdf
yes? use uv.230-2325.ips.cdf
yes? vect/z=1/xskip=3/yskip=3 (u[d=1]-u[d=2]),(v[d=1]-v[d=2])

Both data files are O(337,191,2,1). If you change the last line to:

yes? vect/z=1/xskip=3/yskip=3 (u[d=2]-u[d=1]),(v[d=2]-v[d=1])

you will get 1 and only 1 more command before echo turns off.

This also happens with an NCD Xterm, although it usually takes longer, and even
happens when displaying on the console of the SGI itself. In each of these
cases, it doesn't appear that it is repeatable, i.e., the same commands will
not always result in the loss of echo behavior.

Does anyone have any idea what is going on here, and maybe what to do about it?

Thanks, Mark